1. Field of the Invention
The present invention relates to a fastening apparatus for a pluggable optical transceiver module, and more particularly to a fastening apparatus for a pluggable optical transceiver module adapted to mount and unmount the module.
2. Description of the Related Art
Optical communication systems are used to transmit information in a variety of communication networks or intelligent networks, because such systems can transmit a large quantity of information at high speed using a limited number of circuits.
Such optical communication systems use optical communication switches, which have been developed according to various standard modes, or optical communication apparatuses including optical transceiver modules, such as gigabit interface converters (GBICs), in order to connect electrical signals to input/output optical signals.
The optical transceiver module, as used herein, refers to an optical connector that houses at least a light source apparatus, a light source detection apparatus, an optical transmission circuit, and an optical reception circuit.
Such an optical transceiver module is fabricated according to various standards, which define the specification of the module, to reduce the size of the optical transmission electronic equipment.
An example of an optical transceiver module is an XFP module, i.e., 10 gigabit small form factor pluggable module. In this regard, the XFP MSA (multi-source agreement) revision 3.1 is the standard specification for XFP modules.
FIG. 1 shows the mechanical components of an XFP module 10. The function of main components of the module will now be explained briefly.
The XFP module 10 is a pluggable optical transceiver module. An optical connector 30 acts as the electrical contact portion between a host board 20 and the module. A housing-shaped module case 21 retains the XFP module 10 on the optical connector 30. A heat sink 23 radiates the heat generated by the XFP module 10. A clip 23 retains the heat sink 23 on the cage assembly 21.
FIG. 2 is a side view of the XFP module 10 and the module case 21. The XFP module 10 and the module case 21 will now be explained.
The XFP module 10 has a bail latch 11, which has a ring-shaped groove 12 formed on its end. The groove 12 is latched and retained on a latching portion 21a, which is formed on the module case 21, when the module 10 is mounted on the module case 21. During unmounting, the bail latch 11 separates the groove 12 of the module 10 from the latching portion 21a. 
The latching portion 21a is positioned on both lateral surfaces of the module case 21 and is bent toward the interior thereof.
FIG. 3 is a perspective view showing the front portion of the XFP module 10, which is commercially available. The XFP module 10 includes a bail latch 11, a ring-shaped groove 12 having a slant angle, an insertion hole 13 into which an optical connector 30 is inserted, and a handle 14 for enabling forward or backward operation.
FIGS. 4 and 5 are side views of the XFP module 10 for illustrating the principle of operating the mounting and unmounting of the module 10.
As shown in FIG. 4, when the XFP module 10 is to be mounted, the handle 14 of the module 10 is grasped and rotated down from above to turn it along a downward direction. The ring-shaped groove 12 is then inserted into a U-shaped groove, which is created by the upper and lower covers of the appliance.
In this state, the XFP module 10 is mounted on the module case 21 and the groove 12 is latched on the latching portion 21a and fixedly retained thereby.
As shown in FIG. 5, when the XFP module 10 is to be unmounted, the handle 14 of the module 10 is rotated upward from below to turn it along a horizontal direction. The ring-shaped groove 12 is then moved along direction C1 (marked by an arrow in FIG. 5) away from the U-shaped groove, which is created by the upper and lower covers of the appliance.
Subsequently, the ring-shaped groove 12 is released from the latching portion 21a of the module case 21 and the latching portion 21a, which has been bent toward the interior of the module case 21, is pushed toward the exterior thereof. The module 10 is then unmounted.
In summary, the XFP module 10 adopts a fastening mechanism wherein it is mounted on and unmounted from the module case 21 using its handle 14.
However, such conventional pluggable optical transceiver modules have a problem in that, every time the module is unmounted from the module case (e.g., for experiment, for maintenance and/or for repair during service), the ring-shaped groove of the module must be released from the latching portion of the module case. This causes considerable inconvenience to users.
In particular, the pluggable optical transceiver module is provided on the module case and is fitted with the optical connector. The optical connector must be removed from the module and the handle must be positioned in the horizontal direction, in order to unmount the module. Therefore, when the module needs to be mounted and unmounted frequently, the optical connector should be repeatedly removed and inserted in an inefficient manner.